Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Threat Intelligence

End of Bibblio RCM includes -->
03:15 PM
Connect Directly

Hundreds of Millions of Dell Computers Potentially Vulnerable to Attack

Hardware maker has issued an update to fix multiple critical privilege escalation vulnerabilities that have gone undetected since 2009.

Hundreds of millions of Dell laptops, notebooks, and tablets are at risk of compromise from a set of five high-severity flaws that have been undetected since at least 2009.

The flaws allow an attacker who already has some level of initial access on a system to escalate privileges and gain kernel level access on it.

Related Content:

Dell Releases Security Tool to Defend PCs from BIOS Attacks

Special Report: Assessing Cybersecurity Risk in Today's Enterprises

New From The Edge: Name That Edge Toon: Magical May

Security researchers from SentineOne discovered the bugs in Dell's DBUtil, a driver that is installed and loaded during the BIOS update process on Dell Windows machines. Dell was notified of the issue in December 2020 and has issued an update for it.

In an advisory and FAQ today, the hardware maker offers measures that organizations can take to identify whether they have been impacted and steps they can take to address the issue.

"We remediated a vulnerability (CVE-2021-21551) in a driver (dbutil_2_3.sys) affecting certain Windows-based Dell computers. We have seen no evidence this vulnerability has been exploited by malicious actors to date," a Dell spokeswoman said in an emailed statement, while urging organizations to follow the company's remediations steps as soon as possible.

SentinelOne researchers discovered the vulnerabilities while investigating the security posture of the Dell driver, which has been in use since 2009. The security vendor described Dell as having included the vulnerable driver in BIOS update utilities for literally hundreds of millions of business and consumer computers over the past 12 years.

Four of the five vulnerabilities that SentinelOne discovered in the driver were local elevation of privileges issues, and one resulted in denial-of-service conditions if exploited. Two of the privilege escalation flaws resulted from a memory corruption issue, while the other two stemmed from a lack of input validation. The denial-of-service bug, meanwhile, resulted from a code logic issue.

"We've reported five different vulnerabilities, ranging from trivial to exploit to complex," says Juan Andres Guerrero-Saade, principal threat researcher at SentinelOne. "However, attackers only really need one vulnerability to get kernel-mode privileges."

The bugs give adversaries a way to bypass security products, wipe a hard drive, or install a malicious driver on a domain controller. "The attacker is effectively the system administrator," Guerrero-Saade says.

Dell itself has assigned just one common CVE identifier (CVE-2021-21551) to cover all five flaws. It has identified the issue as being tied to insufficient access control, which could result in privilege escalation and denial of service.

Guerrero-Saade says the risk the vulnerabilities pose to organizations depends on the value and the utility of the impacted system.

"The vulnerabilities allow attackers to escalate privileges from a non-admin user to kernel mode privileges, effectively bypassing account access controls and allowing the attackers to do just about anything on the system," he says.

An attacker needs local access on a system to exploit the issue. But that does not mean the attacker needs actual physical access to it. All that is required is an initial foothold on a system via something as trivial as a malicious attachment, Guerrero-Saade notes.

SentinelOne has not observed any evidence of adversaries having exploited any of the vulnerabilities, so organizations have an opportunity to get ahead of the threat by patching systems as soon as possible, he says.

Not Unusual
Disclosures involving bugs that have remained undiscovered for years in widely used products happen more frequently than some might perceive. Earlier this year, for example, SentinelOne reported a privilege escalation vulnerability in Windows Defender (CVE-2021-24092) that had remained hidden for some 12 years. In January, Qualys disclosed a critical buffer overflow vulnerability in Sudo — a utility in almost all Linux and Unix operating systems — that had remained undiscovered for nearly 10 years. In September 2019, a HackerOne bug-bounty program conducted for the European Union Free and Open-Source Software Audit initiative unearthed a 20-year flaw in PuTTY SSH, an open source file transfer application.

Guerrero-Saade says a couple of reasons likely contributed to the Dell flaws remaining undiscovered for so long.

"Large codebases are unwieldy, difficult to maintain, and often contain a bulk of legacy code that goes unexamined for as long as it appears to be working," he says.

OEM drivers and packages are also generally harder to examine because they are typically packaged with specific systems and there's little guidance around them. The reason why SentinelOne discovered the Dell issues was because an application called Process Monitor, which researchers were using to investigate the driver, alerted them about something being potentially amiss, Guerrero-Saade says.

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
I Smell a RAT! New Cybersecurity Threats for the Crypto Industry
David Trepp, Partner, IT Assurance with accounting and advisory firm BPM LLP,  7/9/2021
Attacks on Kaseya Servers Led to Ransomware in Less Than 2 Hours
Robert Lemos, Contributing Writer,  7/7/2021
It's in the Game (but It Shouldn't Be)
Tal Memran, Cybersecurity Expert, CYE,  7/9/2021
Register for Dark Reading Newsletters
White Papers
Current Issue
The Promise and Reality of Cloud Security
Cloud security has been part of the cybersecurity conversation for years but has been on the sidelines for most enterprises. The shift to remote work during the COVID-19 pandemic and digital transformation projects have moved cloud infrastructure front-and-center as enterprises address the associated security risks. This report - a compilation of cutting-edge Black Hat research, in-depth Omdia analysis, and comprehensive Dark Reading reporting - explores how cloud security is rapidly evolving.
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
PUBLISHED: 2023-02-01
On BIG-IP versions 16.1.x before, 15.1.x before 15.1.8, 14.1.x before, and all versions of 13.1.x, when a SIP profile is configured on a Message Routing type virtual server, undisclosed traffic can cause TMM to terminate. Note: Software versions which have reached End of Technical ...
PUBLISHED: 2023-02-01
On version 14.1.x before, and all versions of 13.1.x, when the BIG-IP APM system is configured with all the following elements, undisclosed requests may cause the Traffic Management Microkernel (TMM) to terminate: * An OAuth Server that references an OAuth Provider * An OAuth profile with t...
PUBLISHED: 2023-02-01
In versions beginning with 7.2.2 to before, a DLL hijacking vulnerability exists in the BIG-IP Edge Client Windows Installer. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
PUBLISHED: 2023-02-01
In BIG-IP starting in versions 17.0.0,,,, and 13.1.5 on their respective branches, a format string vulnerability exists in iControl SOAP that allows an authenticated attacker to crash the iControl SOAP CGI process or, potentially execute arbitrary code. In appliance mode B...
PUBLISHED: 2023-02-01
On versions 17.0.x before, 16.1.x before, 15.1.x before 15.1.7, 14.1.x before, and all versions of 13.1.x, an open redirect vulnerability exists on virtual servers enabled with a BIG-IP APM access policy. This vulnerability allows an unauthenticated malicious attacker to b...